Machine gun assemblies include a barrel for guiding and controlling the direction of a round after it has been expelled from its cartridge as the machine gun assembly is discharged. The barrel includes a chamber for receiving a cartridge prior to discharging the weapon and for housing the cartridge during, and subsequent to, the discharge of the weapon. The barrel further includes a bore which guides the round as it travels through the barrel. The barrel is attached to a barrel extension which, in turn, is mounted to a receiver of the machine gun assembly. The barrel extension includes a slot in which a bolt sub-assembly is mounted. The barrel extension is configured to move with respect to the receiver so it can reciprocate as the machine gun assembly is fired and then recoils, and the bolt sub-assembly is configured to move both together with the barrel extension as the barrel extension moves, and also to move with respect to the barrel extension to permit the loading of unexpended cartridges and the expulsion of expended cartridges. A trigger bar is mounted to the receiver and remains stationary with respect to the receiver. Accordingly, as the barrel extension and the bolt move with respect to the receiver, they also move with respect to the trigger bar.
When the barrel extension and the bolt are in their respective forward positions, the trigger bar comes to rest over a sear. The sear is part of the bolt sub-assembly and is configured to control the release of the firing pin (which is also part of the bolt sub-assembly). When the trigger bar depresses downwardly onto the sear, the sear releases the firing pin which, under the force of a spring, moves rapidly into engagement with the primer of the cartridge. This causes the propellant inside of the cartridge to combust and rapidly expand, thereby expelling the round into the bore, down the barrel, out of the machine gun assembly, and down range.
Modern machine gun assemblies include a barrel that can be quickly released from, and re-engaged with, the barrel extension. In some known examples, such quick release engagement is accomplished through the use of quick release threads. Quick release threads are threads which do not wrap completely around the circumference of the barrel or the barrel extension, but rather, only extend partially around the circumference. The use of quick release threads permit the barrel to be disengaged from, and re-engaged with, the barrel extension by rotating the barrel through only a portion of a rotation (e.g., by turning the barrel sixty or ninety degrees).
In some instances, it has been observed that operators who use the quick release mechanism to disassemble the barrel from the barrel extension may incorrectly re-assemble the machine gun assembly by forgetting to partially rotate the barrel, thereby failing to cause re-engagement between the quick release threads of the barrel and the quick release threads of the barrel extension. Because conventional machine gun assemblies have no means of preventing the weapon from being fired while the barrel is not properly engaged with the barrel extension, the failure to correctly engage the barrel with the barrel extension can lead to undesirable circumstances.
Accordingly, it is desirable to provide a machine gun assembly that is inhibited from being discharged while the barrel is not properly engaged with the barrel extension. In addition, it is desirable to provide an interlock element that can be used to render a machine gun assembly non-dischargeable when the barrel is not properly engaged with the barrel extension. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.